Review: Onkyo TX-NR509 AV receiver

All data were obtained from various test DVDs using 16-bit dithered test signals, which set limits on measured distortion and noise performance. Reference input level is –20 dBFS, and reference output is 1 watt into 8 ohms. Volume setting for reference level was 57. All level trims were at zero. Except for subwoofer-related tests, all speakers were set to “large,” subwoofer on. All are worst-case figures where applicable.

Output at clipping (1 kHz into 8/4 ohms)

1 channel driven: 88/112 W* (19.4/20.5 dBW)

5 channels driven (8 ohms): 28 W* (14.8 dBW)

* The Onkyo produced up to about 120 W mono, and 50 W for 5 channels into 8 ohms, but current-limiting protection dropped output more than 20 dB following periods ranging from a few seconds (levels just over those listed) to a few hundred milliseconds.

Crossover consistency: bass-crossover frequency and slope were consistent for all sources and formats.

Speaker size selection: all channels can be set to “small.”

Speaker-distance compensation: available for all main channels.

Onkyo’s aggressively priced new A/V receiver produced stunningly good bench results on all the low-level tests: Noise, distortion, and frequency response were all excellent, and digital-to-analog performance — as shown by linearity, excess noise, and more — were simply superb. The Onkyo also had plenty of clean, multichannel-mix subwoofer output, something that even expensive receivers don’t necessarily manage.

The TX-NR509’s power output was relatively modest, but it showed thoughtful use of available resources. It had no trouble meeting its single-channel specs and could produce a good deal more for short bursts (fractions of a second) before entering protection mode. When asked to produce more power for longer intervals, it dropped output by about 6 dB. This is the classic solution for a power-supply-limited audio amplifier, where considerable dynamic power remains on tap beyond the steady-state (RMS) measured power, as my listening tests amply confirmed. — D.K.